Circuit-interrupter



1. TRITLE CIRCUIT INTERRUPTER.

APPLICATION FILED APR. 28. I919.

11,323,799. 1 Patented Dec. 2.1919.

III II Inventor John F'. Tr-itle,

y flaw "mm His Att ornay.

. om ED sTATE$ 'P IE JoH'N' 1; TRITLE, OF scnnnnornny, new YORK; ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION on- EW YORK.

CIRCUIT-INTERRUP'I'ER.

Specification of letters Patent.

1919. Seria1 No. 293,1 7.

To .all who 'm it may concern:

"Be 1t. known that. I, JoI-rn of New ,York, have invented-certain. new

. and useful Improvements inCircuit-Inten i'upters, ofwhich the following is a specifi- .-cation. i

. My inventionrel'ates to electric switches and -it has for its principal object the. pro

-vision of improved means whereby electric circuits maybe quickly interrupted.

l This' application is a division of my former application Serial No. 214:,805, filed February 1,1918, which is assigned to the 3' same assignee as this invention In order to preserve a .good electrical con tact surface between the s'witchcontact e1e ments, it is desirable to provide wiping contacts, buttheordin'ary form of such wiping 4 contacts having the yieldingly mounted -contact on the movable switchsmember which is biasedto the open position would tend to defeat the purposeiofithis invention, because the yieldingly mounted contact would leave the stationary contact an appreciable inter- .val of time after. the; switch. member carry-v ing this yieldably mounted contact had begun to move. Oneof the "objects of my 1n-- vention is to provide improved wiping contacts which will retain all the advantagesiof .such contacts, but nevertheless permit the interruption of the circuit as soon as the switch member begins to move;

I accomplisl this' object by. providlng my interrupter with two' movable contact members "having difi'erent moments of inertia, the swltch member which is normally blased to the open position being relatively quite light and the other switch contact being relatively quite heavy, yieldingly mounted and biased toward the light contact so as to givea w1p-- ing action to the contacts in closing. Vhen theinterrupt'er opens in response to abnorheaviercontact in accordance with its bias' f mal conditions, the light switch member will immediately break engagement with the and be accelerated rapidly because of its small moment of '1nert1a.. but the heavier contact will not immediately follow the light contact because of its greater moment of inertia. Speed ininterruption as well as wiping action in closing are thussecured'.

The novel features which'I believe to' be switch contacts.

This winding 4 su1table constant potential source and as p 4 characteristic of my inventionwill be defi- F. TRI E, a .citizen of ,the United States, residing at Schenectady, county of Schenectady, State my invention will be readily; understood from; a consideration of the following description't'akenin' connection with the accompanying drawing whereln- I have shown anembodiment of my invention.

,.Referri11gto the drawing, the single figure shows an embodiment of my inventionmjan interrupter for protectmg a dynamo-j Patented Beet-2, 1919. original application filed Februar 1, 1918, Serial No 214305. Divided and this applieationfiled April 28,

electric machine, from flash-over at-the cominutator. i

The generator, G is protected from flashover at the 'commutatorby means of themiterrupter :2 which 1s adapted to open its switch contacts 111 response to a predeter-=- mined current value and insert the resistance 1' 1n the generator .c1rcu1t, so as tovery I quickly-reduce the current from-the genera- :tor. .T he qulck action lnterrupter 2- V shown in the closed posltion and the sw tch contact member. 3 is held against its bias to the open position bvr'eason of the attraction of the electromagnet for-the ar- 'matureo This-movable switch member 0 is comparatively quite light so, as to have a.

small moment of inertia and thus permit of being opened very quickly by theheavy spring-6 which moves the. switch member to the open position inresponse to a predetermined value of current through the. The shunt coil 7 is p.ro-'

vided for setting up a substantially con. stant flux inthe holding electromagnet 4. may be energlzed from any shown in the drawing it is energized from the generator G. The armature 5 is adaptedato bridge the pole pieces 8 and 9 of the electromagnet and be held there against the bias of the spring v6 until this armature is demagnetmed by the conductor 10 which is 111 ser es wlth, the swltch contacts 11 and .12 and thus responsive tothe current through those contacts.

The conductor 10 is disposed in the air gap 13 which separates the poles Sand 9 of the electromagnet, and

the arrangement issuchthat this conductor is remotelyfdisposed from the winding 7 of the electromagnet and adjacent to the armature. 5. The direction of the magnetic .flux; set up bythe conductor 10 is such that when the cu through the Switch the airgap 13. In other words, the flux of the electromagnet is crowded to the left through this shunt path around the-arma-z time 5, the total 'fi'ux set up-by the-electio' magnet remaining substantially unchanged in value, thussubstantially demagnetizing the armature 5 and.permitting the switch unember 3 to be'moved quickly to the open positions in accordance with'the bias exert the-spri'ng 6; It: will readily be uned by those skilled in the art that the derstoodby rapidly increasing flux set up by theconj tactor 10 upon the occurrence of an overload, such as a short circult for example, will produce a momentary condition in which the magnetic 'fiuX through the armature 5 will-either be entirely suppressed or be so small that it will be insufficient to maintain the switch'member 3 in the closed position against the strong pull of the spring 6. Be-. cause of the position of the. conductor 10 and the arrangement of the parts as shown,

' tion in interrupting the circuit through the there'is substantially no inductive effect between this conductor and the winding 7, the conductor 10 merely acting to change the path of the flux-set up-by the winding 7 without efi'ecting any substantial change in value in the totalflux set up by this winding In order to further insureithat there shall" be no inductive effect betweenthe conductor 10 and the winding 7 and to insure that the armature "will always drop out at the samepoint, the air gap 1% is provided in the magnetic circuit between the conductor and the; Winding. Furthermore, the close proximityof the conductor 10- to the armature 5 will produce 'the maximum effect in demagnetizing the armature-in response to the predeterminedcondition. By making the conductor 10 as straight as possible it has very little inductive efl'ect and is thus more effective inyits action of defleeting the flux ofthe electromagnet. bration of winding? is effected by means of rheostatmh The contact 11 is made as light as'possible consistent with'the c'urrentrequired to e carried, and in fact, all of the-parts of the switch member 3iare made as light as possible so that the 'switchmember -will have the smallest practicable moment of inertia to permit of a very quick acceleraswitch contacts. The movable contact 12,

pivotally mounted ona stationary part of the interrupter purposely made quite heavy so as to have a substantially greater amount of inertia than the switch member 31 This contact 12 is biased toward the contactll by means of the spring 15, thereclosed position.

Caliclosing.

As thus constructed and: arranged, the

operation of my invention is as follows:

any suitable means. "In closby giving a wiping action to the-contacts in movable contact 12 and cause it to turn on 1 "its pivot 17 againstthe bias of the spring 15, thereby giving a wiping action to the contacts.

When the contacts close, the resistan'ce r in the generator circuit'isshort H circuited through a, circuit including the conductor 10, flexible shunt 18, contacts 11 and 12, flexible shunt 19,-and magnetic blowout 'coil 20. The-armature 5 secured to the a the air gap 13' switch member 3 will bridg) between the 'poles 8 and magnet 4 and the switch member 3 will be of the electroheld in this closed position against the bias of thespring 6 by reason of the magnetic;

attraction setup by the flux produced by the shunt-winding 7 'of'the electromagnet. Although substantially the full generator current is flowing through the conductor 10,

provided the current is not in, excess of the predetermined limit, the'flux setup by the winding 7 will not be effected so as to diminish the pull-of the electromagnet below that required to hold the armature 5 in the in the arrangement shown, of the electromagnet will be north and south poles respectivelyand that the magnetic whirl or flux set up by theconductor-IO will It will be understood that the poles 8 and-9 cause a crowding o the lines of force a through the air gap 13 to the left -ofth'e conductor 10 and away fron'r the armature 5. When a' short, circuit or any overload occurs, the crowding eflect will be so great that the path ofsubstantially the entire flux set up-by the winding 7 will be changed and will be deflected from the armature "5 through a shunt path including the air gap 1-3,the total flux of the electromagnettnevertheless remaining substantially constant in Value. When the armature 5 is thus mo-.

mentarily substantially demagnetized, the springtf will cause the switch member 3 to immediately'break the engagement of the.

contacts 11 and 12 and thus quickly interrupt the'circuit. The switch member 3 will be accelerated very rapidly because of having a very small inertia effect, but'the contact 12having a substantially greater inertia efl'ect will not immediately follow-the con-- tact 11, even though it is biased toward the contact 11 by the spring. 15. A very speedy interruptionof the circuit is thus produced and the resistance inserted in the generator. circuit before a flash-over can-occur at the commutator. The 'magnetic. blow-out 20 operates to quickly disrupt any are that may tend to be formed at' the contacts 11, and'12 ina manner ell understood by-those skilled having-'the 'les'ser mbment of-ine 5 inertia efllect "of-Zthe -contact h g-the" electric circuiw p compr1sing a :pair ofj novable circuit mak 1 ing contact members,-one of the members in the art;

- While I- haifei'descrihed i'nyinvention as" embodiedinconcrete form and asioperating' in -.ajspecific'nianner-in accordance with the' provisions "ofsthe patent statutes, itshould 1- be understood that I do not limit my iinvention thereto, since various modifications thereof-will suggest themselves, to those.

skilled in theart without 'departing't'rom .-j the sp'iritof my invention, the scope of which is set forth in-the annexed claims.

.- That I' claim as new and desire to secure.

- by Letters Patent of the United States,is

' making contact members, one of the contacts heing biased toward t'lieother and having a greater moment ofinertia than the other, and means for effecting a movement of the 1' 55- -1. An interrupter for electric circuits,

comprising two movable circuit making wiping contacts, the first contact being biased toward the second contact, and the "inertia effects of the contacts'being'suchthat the second contact will break engagement -with the first before the first can follow the second.

- 2. An interrupter for electric circuits, comprising a pair of wlping contact mem 'bers,"'e ach of which is movable with" respect to the other and one of the members having azgreater moment of inertiatha-n the other,

and means for efiecting a movement of the contact having the lesser moment of in-" ertia to quickly interrupt the electric circuit.-

3. An interrupter for electric circuits,

comprising two biased movable circuit mak-* ing wiping contacts, one of the contacts having a greater moment of inertia'tha-n the other, and means for releasing the contacts 1 from engagement whereby the ci rcuit' is I opened due totheof-therontect: n m'j greater moment of inertia.

' 4, 391" .interru' ter for having a' greater mol nent'of inertia t-hanf the other'and biased'towardthe other, and.

l'neans for moving' the contact having the lesser moment of'inertia to quickly interrupt contact having the lessernioment of inertia, to quickly interrupt the-circuit.

:6. An interrupter for. electric. circuits, compris ng two pivotally mounted movable circuit making. wip ng contacts,t he-first of the contacts ha ingIa'greater'mOment of in"- 'ei'ti'a than the second, means for} biasing the first contact toward thesecond, means for biasing the second contact away' from 'the ffirst, and means for-holding the contacts in engagement, the" release of the holdingmeans eflecting a quick interruption offth'e tact. 4 1

..-In"w itness whereof, Lhave hereunto set my hand this"2'6th daof 'April, 1919. TRI TLE.

icontacts due-to the bias' of the second contact and the inertia'eifect of the first-con 

